Hepes buffer stimulates and Tricine buffer inhibits the growth of Mycoplasma hominis, M. orale and M. salivarium. We propose: (1) to test Hepes, Tricine and other zwitterionic amino acid buffers to determine their effect on the growth of a number of mycoplasmas; (2) to determine the mechanism by which Tricine and Hepes influence mycoplasmal growth; (3) to test the efficacy of Tricine and any other buffers found to inhibit mycoplasmas in treating mycoplasmal diseases; and (4) to define differences between mycoplasmas, and between mycoplasmas and L- phase bacteria using the effects of zwitterionic amino acid buffers on their growth.